The present invention relates to a method of reproducing three-dimensional images, a three-dimensional image-reproducing device and a directional reflective screen, and in particular to techniques useful for the method of reproducing three-dimensional images and the three-dimensional image-reproducing device enabling the observers to see three-dimensional images by binocular parallax without using special glasses.
As a display device for providing three-dimensional images by using the binocular parallax without special glasses, there has been known a device comprising an image projecting means and a directional reflective or transmissive screen. Especially, a directional reflective screen employing a large number of compound mirrors to collect light in a horizontal direction toward the observer is disclosed in xe2x80x9cThree-dimensional Image Technologyxe2x80x9d by T. Ohkoshi, published by Asakura Publishing Company, pp. 28 and 91-97.
The present inventors studied the above prior art three-dimensional image display device, and they found a problem with the prior art display device that a bright exit end of an image projector of the display device is imaged on the three-dimensional images formed by the three-dimensional image display device, this acts as stray light to the observer and degrades the quality of the three-dimensional images.
The present invention aims at solving the problem with the prior art display device, and it is an object of the present invention to provide techniques in the method of reproducing three-dimensional images or the three-dimensional image display device for enabling high-quality three-dimensional images to be observed without the bright exit end of the image projector of the display device being imaged on the three-dimensional images.
It is another object of the invention to provide techniques employed in a directional reflective screen of the three-dimensional image display device and capable of precisely indicating the observer""s position where the observer can observe high-quality three-dimensional images without the bright exit end of the image projector of the display device being imaged on the three-dimensional images.
The above and other objects and novel features of the present invention will be obvious by the following description and the appended drawings.
The summary of representative inventions of the present inventions disclosed in this specification will be briefly explained below.
In a method of reproducing three-dimensional images by a three-dimensional image-reproducing device provided with image projector means and a directional reflective screen for collecting light from the image projector means toward a specific position in a horizontal direction and for diffusing the light from the image projecting means in a vertical direction, the method is characterized in that an observer observing three-dimensional images, said directional reflective screen and said image projecting means are positioned with respect to each other such that the observer is outside a region traversed by a portion of light rays which enter said directional reflective screen from said image projecting means, then are reflected by a surface of said directional reflective screen not contributing to reproduction of the three-dimensional images, and then form a mirror image or a conjugate image of said image projecting means, namely, the observer is in a region where the mirror image or the conjugate image of said image projecting means is not observed by the observer.
Further, in a three-dimensional image-reproducing device provided with image projecting means and a directional reflective screen for collecting light from said image projecting means toward a specific position in a horizontal direction and diffusing the light from said image projecting means in a vertical direction, the three-dimensional image-reproducing device is characterized in that said directional reflective screen and said image projecting means are positioned such that said observer""s position is outside a region traversed by a portion of light rays which enter said directional reflective screen from the image projecting means, then are reflected by a surface of said directional reflective screen not contributing to reproduction of the three-dimensional images, and then form a mirror image or a conjugate image of said image projecting means.
Further, in a directional reflective screen for use in a three-dimensional image-reproducing device, for collecting light from an image projecting means of said device toward a specific position in a horizontal direction and for diffusing the light from the image projecting means in a vertical direction, the directional reflective screen is characterized in that said directional reflective screen is provided with an indicator for indicating that an observer for observing three-dimensional images is outside a region traversed by a portion of light rays which enter said directional reflective screen from the image projecting means, then are reflected by a surface of said directional reflective screen not contributing to reproduction of the three-dimensional images, and then form a mirror image or a conjugate image of the image projecting means, said indicator includes a box having a slit and a light-producing element positioned within said box, a position of said light-producing element being adjustable depending upon a length of said slit and a distance between said image projecting means and said directional reflective screen, and said indicator is configured so as to indicate that the observer is outside said region traversed by the portion of light rays which form a mirror image or a conjugate image of the image projecting means when light from said light-producing element is observed through said slit.